Picture frame



FIG. 1 is a perspective view of a picture frame showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof, the right side being a mirror image; and,

FIG. 5 is a bottom view thereof, the top view being identical but reversed top to bottom. 

The ornamental design for a picture frame, as shown and described. 